The Hot Spring:
The Champagne Pond is a coastal inlet where several hot water springs mix with ocean water. The hot water emerges from several volcanic hot spots in three different coves in the inlet. The inlet is about 100 feet long and each cove is 20-40 feet wide. The water depth changes with the tides, and the coves are protected from ocean waves by a reef. The water is deep during high tide being 8 to 12 feet deep and is about 5 to 8 feet deep during low tide. water bubbles out from the seeps with gas during active times giving the area its name. The temperature varies between 70 and 100 degrees F based on where you are in the inlet, the ambient air temperature, the tides, and how active the seeps are.
The Champagne Pond is located in a private residential community called Beach Lots. Therefore access is technically restricted from the roads, but if you park outside, are respectful and un-intrusive you can walk through the community to the pond. An alternative access is over the 1960 lava flow from the lighthouse on the eastern tip of the big island, but four wheel drive, high clearance, and good tires are required.
Houses are built along most of the coastline and in the center of the inlet between the coves, so bathing suits are required (Hawaiians generally do not like nudity). Shoes should also be worn in the pond because the ground and the walls have sharp edges from the basalt lava flow. Locals use the spot to swim laps, and when I visited there were several locals swimming. One told me why he felt the area was special, in short it was because of; pure pacific ocean water with no land for over 1000 miles, clean tropical air from constant rain, and volcanically heated water from the earth all mixing together. Sea turtles also love The Champagne Pond and relax deep in the coves, paying little attention to the swimmers above their heads.